Because Miss Thomas was trying to convince Calloway to allow Bud to stay with the band while Calloway vehemently disagreed.
In chapter 16, the argument has become more of a discussion. Now the conversation is not just with Miss Thomas and Calloway but with the entire band. Calloway still insists on sending Bud right back to Flint; however, Miss Thomas is still pulling for Bud by stating "You have no idea how bad those orphanages can be. … You'll take care of any stray dog wandering through this neighborhood, but when it comes to a child all of a sudden you have no sympathy. … I believe the child ... He's staying right here."
